Grand marshal is a ceremonial, military, or political office of very high rank. The term has its origins with the word "marshal" with the first usage of the term "grand marshal" as a ceremonial title for certain religious orders. The following are some additional usages of the term grand marshal:

Grand marshal: A person selected at an automobile race (e.g. NASCAR, IndyCar) by the track owner or race sponsor to be the public leader of events on race day or throughout the race weekend. They may have ceremonial duties such as giving the command to start engines, driving the pace car, waving the green flag to start the race, or presenting the trophy to the race winner.

Grand marshal often appears as a rank in science fiction sources, often in space or star fleets whose size requires a rank above such other titles as surface marshal and fleet admiral. Among grand marshal science fiction equivalents include:

Grand marshal: The 14th and highest PvP honor rank of the Alliance in World of Warcraft.

Grand marshal: A rank held by Imperial Guard officers in the Warhammer 40,000 universe. It seems to be assigned to officers who command the armed forces of an entire planet. It is inferior to "lord commander militant".